as far I know only Indonesia Bank, maybe if many people from specific countries have joined, does not rule out the possibility of adding more Bank from other countries. so it could bring more players from other countries.
As far as I remember there are also option to deposit with Malaysian local bank as well as the other local banks as long as the country is listed such as Vietnam and Singapore. BK8 is focused in Asian countries especially South East Asian, so the availability to deposit with local bank is not only for Indonesian players. In other words, once a player created an account and choose a specific fiat money as the main balance (except usd), then there will be a way to deposit with the local bank account as per selected fiat currency.
Maybe they have done an update and add more banks? Because, bk8 has been around in forum for a long time now and they still continue their signature campaigns and other than this forum I also see them being advertised anywhere (in the web, in the app, etc) they probably gained lots users for doing that.
If our local banks is not yet on the list, we can ask them directly to add it, and who knows maybe they will consider our request in the future? But in the meantime, we can still be able to deposit and play by using cryptocurrencies as they also support it. The advantage of using a crypto is that anyone in the world can use it with less restrictions. They are better than banks.